RESUMO O objetivo deste estudo foi avaliar o efeito do regulador de crescimento ácido indolbutírico (AIB) no enraizamento de miniestacas de clones híbridos de Castanea crenata x C. sativa. O enraizamento das miniestacas foi conduzido durante 60 dias em casa de vegetação climatizada e, em seguida, as mudas foram transferidas para casa de sombra, permanecendo por 30 dias. O delineamento experimental utilizado foi em blocos ao acaso, em arranjo fatorial duplo, constituído de cinco concentrações de AIB (0, 2.500, 5.000, 7.500 e 10.000 mg L-1) e cinco clones, com três repetições, compostas de parcelas com oito miniestacas por repetição. O uso de AIB afeta significativamente ao enraizamento e sobrevivência das miniestacas de castanheiro alcançando índices satisfatórios, entretanto se observa que existem diferenças significativas no comportamento dos clones para a mesma dose de AIB, pelo qual se sugerem modificações no processo da propagação adaptando a técnica para cada clone em particular.

ABSTRACT The objective of this study was to evaluate the effect of the growth regulator indole butyric acid (IBA) on the rooting of mini-cuttings of Castanea crenata x C. sativa hybrid clones. Minicuttings were left to root for 60 days in an acclimatized greenhouse and then transferred to a shade house for a further 30 days. The experiment was a random block design with a double factorial arrangement consisting of five IBA concentrations (0, 2,500, 5,000, 7,500 and 10,000 mg L-1) and five clones, with three repetitions, composed of eight minicuttings per repetition. The use of IBA significantly affected the rooting and survival of the mini-cuttings, and good rates were achieved. However, at each IBA concentration we found significant differences between clones, thus suggesting that the conditions of the process of mini-cutting propagation should be specifically adapted to each particular clone.

The importance of chestnut coppice stands in northwestern Spain, together with the almost total lack of growth and yield studies, makes the development of applicable tools to facilitate forest management necessary. In the present study two management tools were developed: variable-density yield tables and stand density management diagrams (SDMDs). For constructing the yield tables, a dominant height growth model and a stand density model were fitted. The dominant height growth model was necessary for estimating site index, i.e., for indirectly assessment of site quality. A stand density model was necessary because the silvicultural stages of the stands were very heterogeneous. Both yield tables and SDMDs require fitting models for predicting quadratic mean diameter and growing stock (total or merchantable stand volume and/or total or component stand biomass). Eight yield tables were constructed considering two stand density levels (high and low) and four site indices (8, 12, 16 and 20 m). Rotation lengths producing maximum sustainable yield ranged between 25 and 45 years depending on stand density class and site index. Average growth at these rotation lengths varied from 38.1 m³ ha-1 year-1 for the highest density and best quality, to 5.2 m³ ha-1 year-1 for the lowest density and poorest quality. Both the yield tables and the SDMDs developed allow estimation of total and merchantable stand volume, total and component stand biomass and also facilitate the design of silvicultural schedules.

La importancia del monte bajo de castaño en el noroeste de España, junto con la falta de estudios de crecimiento y producción, hacen necesario el desarrollo de herramientas que faciliten su gestión. En este estudio se han desarrollado dos herramientas de gestión: tablas de producción de densidad variable y diagramas de manejo de densidad (DMDs). Para la construcción de las tablas de producción se ajustaron un modelo de altura dominante y uno de densidad de masa. El modelo de altura dominante proporciona el índice de sitio, es decir, estimar indirectamente la calidad de estación. Se necesitó un modelo de densidad porque los escenarios selvícolas eran muy heterogéneos. Tanto las tablas de producción como los DMDs requieren el ajuste de modelos de predicción de diámetro medio cuadrático y stock de crecimiento (volumen total y comercial de masa y/o biomasa total o por componentes). Se construyeron ocho tablas de producción considerando dos niveles de densidad de masa (alta y baja) y cuatro índices de sitio (8, 12, 16 y 20 m). El turno de máxima renta en especie varió entre 25 y 45 años según la clase de densidad y el índice de sitio. El crecimiento medio osciló desde 38,1 m³ ha-1 año-1 para las densidades más elevadas y mejores calidades, hasta 5,2 m³ ha-1 año-1 en las densidades más bajas y peores calidades. Las herramientas de gestión desarrolladas permiten la estimación del volumen total y comercial de masa, biomasa total y por componentes y también facilitan el diseño de esquemas selvícolas.